Abstract
Background and purpose
Photon-counting detector CT (PCD-CT) offers improved spatial resolution compared with conventional energy-integrating detector CT (EID-CT), but session-level dose comparisons in multiacquisition CT myelography (CTM) are limited. We compared radiation dose between PCD-CTM and EID-CTM for detecting CSF-venous fistulas (CVFs) in patients with spontaneous intracranial hypotension (SIH).Materials and methods
This retrospective, single-center cohort study included 603 CTM examinations (EID-CTM, n=470; PCD-CTM, n=133) performed for SIH evaluation between 2020 and 2025. The primary end point was session dose-length product (DLP) for the entire CTM examination. Secondary end points included diagnostic-series volume CT dose index (CTDIvol) and DLP in CVF-positive examinations (Duke CSF-Venous Fistula Confidence Score ≥2) and a scan length proxy (diagnostic DLP/CTDIvol). Radiation dose metrics were compared using nonparametric tests and reported as median (interquartile range).Results
Session DLP was significantly lower for PCD-CTM than for EID-CTM: 1760 (1277-2206) vs 5030 (3476-6559) mGy·cm (median reduction, 65.0%; P vol (median reduction, 79.9%; P P P P Conclusions
In patients undergoing CT myelography for CVF evaluation, PCD-CTM was associated with an approximately 65% lower session-level radiation dose than EID-CTM, despite covering a longer anatomic range and more acquisitions.